EXHIBIT 99.6
 
            GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION
                         NUMBER ON SUBSTITUTE FORM W-9
 
GUIDELINES FOR DETERMINING THE PROPER IDENTIFICATION NUMBER TO GIVE THE
PAYER--Social Security numbers have nine digits separated by two hyphens: i.e.
000-00-0000. Employer identification numbers have nine digits separated by
only one hyphen: i.e. 00-0000000. The table below will help determine the
number to give the payer.
 
- --------------------------------------- ---------------------------------------


                              GIVE THE
FOR THIS TYPE OF ACCOUNT:     SOCIAL SECURITY
                              NUMBER OF--
- -----------------------------------------------
                           
1. An individual's account    The individual
2. Two or more individuals    The actual owner
 (joint account)              of the account
                              or, if combined
                              funds, any one of
                              the
                              individuals(1)
3. Husband and wife (joint    The actual owner
 account)                     of the account
                              or, if
                              joint funds,
                              either person(1)
4. Custodian account of a     The minor(2)
 minor (Uniform Gift to
 Minors Act)
5. Adult and minor (joint     The adult or, if
 account)                     the minor is the
                              only contributor,
                              the minor(1)
6. Account in the name of     The ward, minor,
 guardian or committee for a  or incompetent
 designated ward, minor, or   person(3)
 incompetent person
7. a. The usual revocable     The grantor-
      savings trust account   trustee(1)
      (grantor is also
      trustee)
b. So-called trust account    The actual
   that is not a legal or     owner(1)
   valid trust under State
   law



                               GIVE THE EMPLOYER
FOR THIS TYPE OF ACCOUNT:      IDENTIFICATION
                               NUMBER OF--
                                        --------
                            
 8. Sole proprietorship        The owner(4)
  account
 9. A valid trust, estate, or  The legal entity
  pension trust                (do not furnish
                               the identifying
                               number of the
                               personal
                               representative or
                               trustee unless
                               the legal entity
                               itself is not
                               designated in the
                               account title)(5)
10. Corporate account          The corporation
11. Partnership account held   The partnership
  in the name of the business
12. Association, club,         The organization
  religious, charitable,
  educational or other tax-
  exempt organization
13. A broker or registered     The broker or
 nominee                       nominee
14. Account with the           The public entity
  Department of Agriculture
  in the name of a public
  entity (such as a State or
  local government, school
  district, or prison) that
  receives agricultural
  program payments

                                        ---------------------------------------
- ---------------------------------------
 
(1) List first and circle the name of the person whose number you furnish.
(2) Circle the minor's name and furnish the minor's social security number.
(3) Circle the ward's, minor's or incompetent person's name and furnish such
    person's social security number.
(4) You must show your individual name, but you may also enter your business
    or "doing business as" name. You may use either your social security
    number or employer identification number.
(5) List first and circle the name of the legal trust, estate, or pension
    trust.
 
NOTE: If no name is circled when there is more than one name, the number will
      be considered to be that of the first name listed.

 
            GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION
                         NUMBER ON SUBSTITUTE FORM W-9
                                    PAGE 2
OBTAINING A NUMBER
If you don't have a taxpayer identification number or you don't know your
number, obtain Internal Revenue Service Form SS-5 (Application for Social
Security Number Card) or Form SS-4 (Application for Employer Identification
Number) from your local office of the Social Security Administration or the
Internal Revenue Service and apply for a number.
 
PAYEES EXEMPT FROM BACKUP WITHHOLDING
Payees specifically exempted from backup withholding on ALL payments include
the following:
 . A corporation.
 . A financial institution.
 . An organization exempt from tax under Section 501(a) of the Internal
   Revenue Code of 1986, as amended (the "Code"), or an individual retirement
   plan or a custodial account under Section 403(b)(7) of the Code.
 . The United States or any agency or instrumentality thereof.
 . A State, the District of Columbia, a possession of the United States or any
   subdivision or instrumentality thereof.
 . A foreign government, a political subdivision of a foreign government, or
   any agency or instrumentality thereof.
 . An international organization or any agency or instrumentality thereof.
 . A registered dealer in securities or commodities registered in the United
   States or a possession of the United States.
 . A real estate investment trust.
 . A common trust fund operated by a bank under Section 584(a) of the Code.
 . An exempt charitable remainder trust, or a non-exempt trust described in
   Section 4947(a)(1) of the Code.
 . An entity registered at all times under the Investment Company Act of 1940.
 . A foreign central bank of issue.
 
PAYMENTS EXEMPT FROM BACKUP WITHHOLDING
Payments of dividends and patronage dividends not generally subject to backup
withholding include the following:
 . Payments to nonresident aliens subject to withholding under Section 1441 of
   the Code.
 . Payments to partnerships not engaged in a trade or business in the United
   States and which have at least one nonresident partner.
 . Payments of patronage dividends where the amount received is not paid in
   money.
 . Payments made by certain foreign organizations.
 . Payments made to a nominee.
 Payments of interest not generally subject to backup withholding include the
following:
 . Payments of interest on obligations issued by individuals. NOTE: You may be
   subject to backup withholding if this interest is $600 or more and is paid
   in the course of the payer's trade or business and you have not provided
   your correct taxpayer identification number to the payer.
 . Payments of tax-exempt interest (including exempt interest dividends under
   Section 852 of the Code).
 . Payments described in Section 6049(b)(5) of the Code to nonresident aliens.
 . Payments on tax-free covenant bonds under Section 1451 of the Code.
 . Payments made by certain foreign organizations.
 . Payments made to a nominee.
Exempt payees described above should file Substitute Form W-9 to avoid
possible erroneous backup withholding. FURNISH YOUR TAXPAYER IDENTIFICATION
NUMBER, WRITE "EXEMPT" ON THE FACE OF THE FORM, SIGN AND DATE THE FORM AND
RETURN IT TO THE PAYER. IF YOU ARE A NONRESIDENT ALIEN OR A FOREIGN ENTITY NOT
SUBJECT TO BACKUP WITHHOLDING, FILE WITH PAYER A COMPLETED INTERNAL REVENUE
FORM W-8 (CERTIFICATE OF FOREIGN STATUS).
 Certain payments other than interest, dividends, and patronage dividends that
are not subject to information reporting are also not subject to backup
withholding. For details, see Sections 6041, 6041A(a), 6045, and 6050A of the
Code.
PRIVACY ACT NOTICE--Section 6109 of the Code requires most recipients of
dividend, interest or other payments to give taxpayer identification numbers
to payers who must report the payments to the Internal Revenue Service. The
Internal Revenue Service uses the numbers for identification purposes and to
help verify the accuracy of your tax return. Payers must be given the numbers
whether or not recipients are required to file tax returns. Payers must
generally withhold 31% of taxable interest, dividends and certain other
payments to a payee who does not furnish a taxpayer identification number to a
payer. Certain penalties may also apply.
 
PENALTIES
(1) PENALTY FOR FAILURE TO FURNISH TAXPAYER IDENTIFICATION NUMBER--If you fail
to furnish your taxpayer identification number to a payer, you are subject to
a penalty of $50 for each such failure, unless your failure is due to
reasonable cause and not to willful neglect.
(2) CIVIL PENALTY FOR FALSE INFORMATION WITH RESPECT TO WITHHOLDING--If you
make a false statement with no reasonable basis which results in no imposition
of backup withholding, you are subject to a penalty of $500.
(3) CRIMINAL PENALTY FOR FALSIFYING INFORMATION--Wilfully falsifying
certifications or affirmations may subject you to criminal penalties,
including fines and/or imprisonment.
(4) FAILURE TO REPORT CERTAIN DIVIDEND AND INTEREST PAYMENTS--If you fail to
include any portion of an includable payment for interest, dividends, or
patronage dividends in gross income, such failure will be subject to a penalty
of 5% on any portion of an under-payment attributable to that failure unless
there is clear and convincing evidence to the contrary.
FOR ADDITIONAL INFORMATION CONTACT YOUR OWN TAX ADVISOR OR THE INTERNAL
REVENUE SERVICE